This invention relates to an automated smoking machine for the collection and analysis of CO and TPM.
Machines to smoke cigarettes and analyze TPM have been used for many years to determine tar and nicotine levels. Within the industry, standard sample and analysis criteria have been established. Standards for puff volume, puff profile and puff duration, together with sample preparation and analysis, have been set by the U.S. Federal Trade Commission. Cigarette smoking machines must be built to produce puffs conforming to those standards, as set forth in, "Tar and Nicotine in Cigarette Smoke," Pillsbury, et al., Journal of the Association of Official Analytical Chemists, 52:458-462 (1969).
Such criteria provide a standard, uniform analytical technique to produce reproducible results between various testing laboratories for the determination of TPM and nicotine in cigarettes. In general, the standards provide for a puff volume of 35 ml measured as the volume of smoke that will be drawn from a cigarette per puff under actual machine smoking conditions. The duration of each puff is defined as being approximately 2 seconds, with the puff frequency of 1 puff per minute. By use of filters interposed between the cigarettes and the mechanism for generating a puff, the collection of TPM can be made.
A host of devices have been proposed and developed within the prior art. Typical machines for smoking cigarettes which are typified by U.S. Pat. Nos. 2,228,216 to Morgan; 3,200,648 to Waggaman; 3,433,054 to Mutter; 3,460,374 to Parks; 3,476,119 to Walton; 3,528,435 to Morrissey; 3,548,840 to Baumgartner; 3,548,841 to Caughui; 3,732,874 to Wagner, et al.; and 4,019,366 to Chalfin, et al. The hallmark of all of those devices is that they essentially deal with a parallel or all-at-a-time type of device. Hence, each cigarette in the group of 20 is puffed simultaneously once every 60 seconds, with TPM collected at each station. Such a device, while allowing for the adequate collection of TPM, cannot be used to deliver filtered gas from each discrete puff to a gas analyzer with minimum delay. Hence, determination of CO levels in such prior art machines is difficult, if not virtually impossible, to accomplish on a reliable and reproducible basis. Typical of such parallel-type machines is the automated 20-port smoking machine, Model 9900-100, manufactured by Phipps & Bird, Inc., Richmond, Va., which are discussed in the Pillsbury, et al. article.
The present invention is a specific improvement over the prior art parallel type of cigarette smoking machines.